Thirty-six of the 112 arrested people -- 32 percent -- were registered in Oregon but didn't return ballots, according to data compiled by the Multnomah County Elections Division.

The data showed 31 people -- 28 percent -- did vote in Oregon.

But the figures leave unanswered questions:

The Elections Division determined that another 36 of the people weren't registered in Oregon at the time of the Nov. 8 election -- but that doesn't mean they weren't registered in another state, said spokesman Eric Sample.

There's no specific time period when someone living in Oregon must register to vote here instead of their home state, he said. That's particularly common among out-of-state college students.

So it's possible that some or all of those 36 people who weren't registered in Oregon could have voted in other states.

What's more, Sample said, a state-by-state search would be necessary to determine whether those 36 people are registered elsewhere.

The Election Division also wasn't able to account for the voter participation of five protesters because it lacked middle names for those people or birth dates.

Of the 112 protesters who were arrested, four were under age 18 -- in other words, too young to vote.

The Elections Division came up with the results after running the names and ages of the protesters through its Oregon database and looking for matches in response to a public records request by KGW-TV. The Elections Division also provided the results Tuesday to The Oregonian/OregonLive, but the numbers are different from those reported by KGW, in part because the division had updated information.

The Oregonian/OregonLive is independently researching who among the arrested protesters voted in Oregon as well as Washington, by checking voter participation records. But, like the Elections Division, the news organization has run into some roadblocks, such as acquiring the arrested person's date of birth to make a match to voter records.